F. R. Petiierbridge 9 



On hatching it measures 1*9—2-1 mm. and when full grown 9-5-11 mm. 

 in length. In the young larval stages the body is of a dirty white or 

 dirty yellow colour and the short legs are brownish black, except at 

 their bases, which are greenish. The head and body are hairy as in the 

 later stages (see PI. I, fig. 2). 



In the older stages the head is yellowish, semi-transparent, with light 

 brown splashes on the vertex, and with a pair of black spots on each side, 

 which are not visible when the caterpillar is looked at from above. The 

 anterior of these spots is situated just behind and below the antenna 

 and round the group of eyes. The posterior one is situated at the same 

 level near the posterior margin (see PL I, fig. 2). 



The first thoracic plate is of a pale yellowish colour in those larvae 

 which have a yellowish head. These later stage larvae have legs of a 

 yellowish brown colour. 



The body is at first of a dirty white or dirty yellow colour, but later 

 on may be either a dull yellowish green, a yellowish brown or a dull 

 green colour. 



The dorsal vessels appear as a dark green line down the middle of 

 the body and can be seen pulsating. On each side of it is a sub-dorsal 

 line of a dark colour. 



The pupa is 6-5-7-5 mm. in length and very variable in colour. At 

 first the head is brown, the wing cases green and the abdomen brownish 

 yellow; but later on the green colour usually disappears and the wing 

 cases become yellowish brown and the abdomen reddish brown. 



The moths are also very variable in colour. The triangular patch on 

 the fore wing may be of a rich brown colour or almost black. 



Parasitism. In 1918 both broods of caterpillars were badly parasitised 

 by the larvae of a small Chalcid 1 . As many as 35 Chalcids were reared 

 from a single caterpillar. The larvae eat the inside of the caterpillar and 

 leave only the skin. The outline of each larva can be seen through the 

 transparent skin. They cause the skin to bulge. The first brood of adult 

 chalcids appears in July, and although I found chalcid pupae in October 

 I have no record of the date of appearance of the second brood of adults. 

 A single pupa was found containing a large hymenopterous parasite, but 

 this did not mature. 



Remedial measures. 



In 1918 I tried the effect of spraying attacked plants with Lead 

 Arsenate and with powders containing Calcium Arsenate and Calcium 



1 A description of the parasite is published on p. 2 of this number of the Journal. 



